The Tissue Culture Media Resource is a centralized laboratory that functions to provide high quality and low cost custom and standard tissue culture media, sterile buffers, and high purity water to RPCI laboratories. Savings are generated by bulk purchases of dry media components, and preparation of large batches of media. Quality is ensured by rigorous quality control standards and use of high purity water for media preparation. Moreover, use of high quality water ensures batch-to-batch consistency, and thus consistency of experimental results. This widely utilized service adds value by providing substantial cost savings to investigators, while simultaneously improving the efficiency of each of the CCSG programs.